i would like to just point out that this page should be composed of concise and accurate notes on things such as who when where what why. there is no point of maintaining this page if people are just going to copy and paste wikipedia articles.
Causes of the Scientific Revolution The expansion of trade. Merchants undertook sea voyages and had navigational problems. These problems had to be solved and, as a result, there appeared scientific thought and research for finding possible solutions.
Medieval Universities. The philosophical talks and ancient philosophers’ studies, such as Aristotle and William Ockham, aroused interest and caused the thought.
The Renaissance was a period of great cultural development in Western Europe. It started in the 14th century. Leonardo da Vinci and Plato were interested in Mathematics. Thus, people became interested in this discipline too, because of the influence of great masters. The most significant changes occurred in biology (blood circulation study), astronomy (invention of a new universe model), chemistry (discovery elements of nature) and physics (invention of laws of gravitation and motion).
The progress of logic and knowledge of the physical world during the Scientific Revolution was constantly at odds with the oppositional force of religion and mysticism. How were average Europeans, and the scientists themselves, affected by the dilemma created by these forces? In the lives of the impoverished masses, stability was of the utmost importance. In the face of the instability and change threatened by advancement of science, common Europeans often turned to the Church for guidance. The combination of the influence of the Church and the traditions which had been passed down for hundreds of years produced an attitude of mysticism that seemed to answer all of the difficult questions of everyday life. Events in the natural world occurred not because of the interaction of mechanical forces but because of the influence of the positioning of the planets. This was a convenient and well-ingrained belief system. In fact, this belief system was so ingrained that even scientists themselves often fell prey to it I.e. Johannes Kepler was convinced that the universe had to be arranged according to some grand scheme, and that the teachings of astrology were largely correct. In keeping with these ancient beliefs, Kepler searched for a simple geometric model of the universe, largely ignoring the evidence to the contrary. Kepler's was a common dilemma faced by the thinkers of the sixteenth and seventeenth centuries. The ancient traditions exercised a strong pull on many scientists, who often allowed the supposed authorities of the past, or even simply the spirit of the past, to cloud their judgment and limit the progress made by their work. How did the scientific view regarding authority change during the Scientific Revolution? During the Middle Ages, science was undertaken more often in the library than in the laboratory. Even Nicolas Copernicus was content to synthesize the ideas and records of others rather than to directly collect and test his own data. However, during the later sixteenth century, attitudes toward additional authority were changing. Men were no longer content to rely on ancient authority for the truth. Instead, they sought to do their own experimentation and observation. Nowhere was this more true than in the Royal Society. The society instituted the method of scientific inquiry most unfavorable to the persistence of dogmatism: laboratory experimentation. To quote past authority was useless, and frowned upon. The crest of the Royal Society bears the motto Nullius in verba ('On the word of no man'). This motto expresses the demand for tangible evidence, for repeatable experimentation, which created the spirit of science, as we know it today. Royal Society - The Royal Society of London brought together the greatest minds of the region in efforts to advance science through cooperation. The Royal Society of London, and other scientific societies that grew up in Europe during the later seventeenth century, contributed greatly to the scientific progress made during that period. Doctrine of Uniformity - The doctrine of uniformity was an enormous step in the quest to integrate physics and astronomy. Developed by Galileo in his Dialogue on the Two Chief Systems of the World, the doctrine of uniformity states that corresponding causes produce corresponding affects throughout the universe. Thus, terrestrial physics may be used to explain the motion of heavenly bodies. Geocentric - The term geocentric describes the theory on the organization of the universe presented by Ptolemy of ancient Greece, and incorporated into the Aristotelian system, which claims that the earth is the center of the solar system and that the sun and other planets orbit around it. Heliocentric - The term heliocentric describes the correct theory, first posed by Nicolas Copernicus, that the Earth is simply one of several planets which orbit the sun. Francis Bacon - Bacon (1561-1626) was one of the great philosophers of the Scientific Revolution. His thoughts on logic and ethics in science and his ideas on the cooperation and interaction of the various fields of science, presented in his work Novum Organum, have remained influential in the scientific world to this day. Galileo Galilei - Galileo (1564-1642) was the most successful scientist of the Scientific Revolution, save only Isaac Newton. He studied physics, specifically the laws of gravity and motion, and invented the telescope and microscope. Galileo eventually combined his laws of physics with the observations he made with his telescope to defend the heliocentric Copernican view of the universe and refute the Aristotelian system in his 1630 masterwork, Dialogue on the Two Chief Systems of the World. Upon its publication, he was censored by the Catholic Church and sentenced to house arrest in 1633, where he remained until his death in 1642. Johannes Kepler - Kepler (1571-1630) studied the orbits of the planets and sought to discern some grand scheme that defined the structure of the universe according to simple geometry. Though he was unable to do accomplish his goal, he did come up with the laws of planetary motion, which explained the orbital properties of planets, and factored extensively into Isaac Newton's later work. Three laws of planetary motion: 1. The movement of the planets is a regular elliptical orbit, with the sun as a focus 2. Planets move in a velocity in which equal areas are swept out in equal times 3. The square of the period of the orbit of a planet is proportional to the cube of the planet’s mean distance from the sun.
All heavens are bound in a single mathematical relationship.
Universe was a lawful mechanical system, expressed in mathematics. The model put forth by Copernicus acquired greater status. Isaac Newton - Perhaps the most influential scientist of all time, Newton (1642-1727) took the current theories on astronomy a step further and formulated an accurate comprehensive model of the workings of the universe based on the law of universal gravitation. Newton explained his theories in the 1687 revolutionary work Philosophia Naturalis Principia Mathematica, often called simply the Principia. This work also went along way toward developing calculus.
Copernicus (1473-1543) Ptolemy and Aristotle’s work with an overlay of Christian perceptions were the basis of old views of cosmos. 10 heavenly spheres revolved around the immobile Earth and to each sphere were attached heavenly bodies that moved with them. The higher the sphere the more perfect it was and the last sphere was the home of God. The geographical centre was Jerusalem, the holy city. Circular motion—the motion of the spheres was seen as circular, or perfect. Humans had special relationship with God, so they were at the centre of the universe. Proposed the first substantive challenge to medieval cosmology, which had become very complex by the fifteenth century On the Revolutions of the Heavenly Bodies (1543)- Ptolemaic model was wrong: cosmos is heliocentric (sun-centred) rather than geocentric (Earth-centred). This system was a hypothesis and it did not provide quantities of evidence from observation to support its claims. Copernicus’s work was controversial. Natural Rights (from Two Treatises of Government 1690) Locke believed that humans, in a “state of nature (a time when there was no society or civilization)” are governed by law of nature (reason teaches all mankind that everyone is equal and independent and no one ought to harm another in his life, health, liberty, or possessions. However, Locke believed that over time, the state of nature would become unsatisfactory and people would become quarrelsome and acquisitive. They would need a system of government that would guarantee life, freedom, and protection of property; and in establishing a sovereign authority, people retained their natural rights, which they had in the state of nature. People could not alienate their life, liberty, and property and government existed in order to protect these rights, and therefore, only limited powers were to be given to it. Social contract was made between individuals to establish an authority and then a contract between the governing authority and the people were made to limit the power of the government. This ultimately advanced the doctrine of civil liberty.
*more to follow. Made some of the notes by hand in class, so when I get them, I will add more to the page.
Sooo.
Intellectual Elements: (add your stuff underneath)
(Ilya) ___
History Notes on Intellectual (1555-1648) Locke
John Locke (pronounced /ˈlɒk/; 29 August 1632 – 28 October 1704), widely known as the Father of//Liberalism//,[2][3][4] was an Englishphilosopher and physician regarded as one of the most influential of Enlightenment thinkers. Considered one of the first of the Britishempiricists, following the tradition of Francis Bacon, he is equally important to social contract theory. His work had a great impact upon the development of epistemology and political philosophy. His writings influenced Voltaire and Rousseau, many Scottish Enlightenmentthinkers, as well as the American revolutionaries. His contributions to classical republicanism and liberal theory are reflected in theAmericanDeclaration of Independence.[5]
Locke Says that and object has certain inherent qualities distinct from perception of it, qualities that it would have even if it were not perceived. The primary Qualities. Size, shape, weight. Secondary qualities. Color, Smell, texture, taste. These qualities are not within the object itself. We make them up, we get the sensation of them. Sense Data are the images or sensory impressions, immediate contents of sensory experience. It is not the outer object that is present in the consciousness.
3 Factors involved in perception: Perceiver, knower, the entity or object.
Hobbes Thomas Hobbes(5 April 1588 – 4 December 1679), in some older texts Thomas Hobbs of Malmsbury,[1] was an Englishphilosopher, best known today for his work on political philosophy. His 1651 book //Leviathan//established the foundation for most of Western political philosophy from the perspective of social contract theory.[2] Hobbes was a champion of absolutism for the sovereign but he also developed some of the fundamentals of European liberal thought: the right of the individual; the natural equality of all men; the artificial character of the political order (which led to the later distinction between civil society and the state); the view that all legitimate political power must be "representative" and based on the consent of the people; and a liberal interpretation of law which leaves people free to do whatever the law does not explicitly forbid.[3] Hobbes also contributed to a diverse array of fields, including history, geometry, physics of gases, theology, ethics, general philosophy, and political science. His account of human nature as self-interested cooperation has proved to be an enduring theory in the field of philosophical anthropology. He was one of the key founders of materialism in philosophy.
Descartes René Descartes(French pronunciation: [ʁəne dekaʁt]; 31 March 1596 – 11 February 1650) (Latinized form: Renatus Cartesius; adjectival form: "Cartesian")[2] was a French philosopher, mathematician, physicist, and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the "Father of Modern Philosophy", and much subsequent Western philosophy is a response to his writings, which are studied closely to this day. In particular, his //Meditations on First Philosophy//continues to be a standard text at most university philosophy departments. Descartes' influence in mathematics is also apparent; the Cartesian coordinate system—allowing geometric shapes to be expressed in algebraic equations—was named after him. He is credited as the father of analytical geometry. Descartes was also one of the key figures in the Scientific Revolution. Descartes frequently sets his views apart from those of his predecessors. In the opening section of the //Passions of the Soul//, a treatise on the Early Modern version of what are now commonly called emotions, Descartes goes so far as to assert that he will write on this topic "as if no one had written on these matters before". Many elements of his philosophy have precedents in late Aristotelianism, the revived Stoicismof the 16th century, or in earlier philosophers like St. Augustine. In his natural philosophy, he differs from the Schools on two major points: First, he rejects the analysis of corporeal substance into matter and form; second, he rejects any appeal to ends—divine or natural—in explaining natural phenomena.[3] In his theology, he insists on the absolute freedom of God’s act of creation. Descartes was a major figure in 17th-century continental rationalism, later advocated by Baruch Spinoza and Gottfried Leibniz, and opposed by the empiricist school of thought consisting of Hobbes, Locke, Berkeley, Jean-Jacques Rousseau, and Hume. Leibniz, Spinoza and Descartes were all well versed in mathematics as well as philosophy, and Descartes and Leibniz contributed greatly to science as well. As the inventor of the Cartesian coordinate system, Descartes founded analytic geometry, the bridge between algebra and geometry, crucial to the discovery of infinitesimal calculus and analysis. He is perhaps best known for the philosophical statement "//Cogito ergo sum//" (French: Je pense, donc je suis; English: I think, therefore I am; or I am thinking, therefore I exist or I do think, therefore I do exist), found in part IV of//Discourse on the Method//(1637 – written in French but with inclusion of "Cogito ergo sum") and §7 of part I of //Principles of Philosophy//(1644 – written in Latin).
Gogito Ergo Sum ogito ergo sum(French: Je pense donc je suis; English: I think, therefore I am), often mistakenly stated as Dubito ergo cogito ergo sum(English: "I doubt, therefore I think, therefore I am"),[1] is a philosophicalLatin statement used by René Descartes, which became a fundamental element of Western philosophy. The simple meaning of the phrase is that if someone wonders whether or not he exists, that is, in and of itself, proof that he does exist (because, at the very least, there is an "I" who does the thinking).[2] It forms the bedrock for all knowledge, because, while all things can be questioned as to whether they are from the realm of reality or from some figment of imagination (a dream, influence of a demon, etc.), the very act of doubting one's own existence serves as proof of the reality of one's own existence. A common mistake is that people take the statement as proof that they, as a human person, exist. However, it is a severely limited conclusion that does nothing to prove that one's own body exists, let alone anything else that is perceived in the physical universe. It only proves that one's mind exists (that part of an individual that observes oneself doing the doubting). It does not rule out other possibilities, such as waking up to find oneself to be a butterfly who had dreamed of having lived a human life. Descartes's original statement was "Je pense donc je suis," from his //Discourse on Method//(1637). He wrote it in French, not in Latin and thereby reached a wider audience in his country than that of scholars. He uses the Latin "Cogito ergo sum" in the later //Principles of Philosophy//(1644), Part 1, article 7: "Ac proinde hæc cognitio, ego cogito, ergo sum, est omnium prima & certissima, quæ cuilibet ordine philosophanti occurrat." (English: "This proposition, I think, therefore I am, is the first and the most certain which presents itself to whomever conducts his thoughts in order."). At that time, the argument had become popularly known in the English speaking world as 'the "Cogito Ergo Sum" argument', which is usually shortened to "Cogito" when referring to the principle virtually everywhere else.
there is no point of maintaining this page if people are just going to copy and paste wikipedia articles.
Causes of the Scientific Revolution
The expansion of trade. Merchants undertook sea voyages and had navigational problems. These problems had to be solved and, as a result, there appeared scientific thought and research for finding possible solutions.
Medieval Universities. The philosophical talks and ancient philosophers’ studies, such as Aristotle and William Ockham, aroused interest and caused the thought.
The Renaissance was a period of great cultural development in Western Europe. It started in the 14th century. Leonardo da Vinci and Plato were interested in Mathematics. Thus, people became interested in this discipline too, because of the influence of great masters.
The most significant changes occurred in biology (blood circulation study), astronomy (invention of a new universe model), chemistry (discovery elements of nature) and physics (invention of laws of gravitation and motion).
The progress of logic and knowledge of the physical world during the Scientific Revolution was constantly at odds with the oppositional force of religion and mysticism. How were average Europeans, and the scientists themselves, affected by the dilemma created by these forces?
In the lives of the impoverished masses, stability was of the utmost importance.
In the face of the instability and change threatened by advancement of science, common Europeans often turned to the Church for guidance.
The combination of the influence of the Church and the traditions which had been passed down for hundreds of years produced an attitude of mysticism that seemed to answer all of the difficult questions of everyday life.
Events in the natural world occurred not because of the interaction of mechanical forces but because of the influence of the positioning of the planets. This was a convenient and well-ingrained belief system.
In fact, this belief system was so ingrained that even scientists themselves often fell prey to it
I.e. Johannes Kepler was convinced that the universe had to be arranged according to some grand scheme, and that the teachings of astrology were largely correct.
In keeping with these ancient beliefs, Kepler searched for a simple geometric model of the universe, largely ignoring the evidence to the contrary. Kepler's was a common dilemma faced by the thinkers of the sixteenth and seventeenth centuries. The ancient traditions exercised a strong pull on many scientists, who often allowed the supposed authorities of the past, or even simply the spirit of the past, to cloud their judgment and limit the progress made by their work.
How did the scientific view regarding authority change during the Scientific Revolution?
During the Middle Ages, science was undertaken more often in the library than in the laboratory. Even Nicolas Copernicus was content to synthesize the ideas and records of others rather than to directly collect and test his own data. However, during the later sixteenth century, attitudes toward additional authority were changing.
Men were no longer content to rely on ancient authority for the truth. Instead, they sought to do their own experimentation and observation.
Nowhere was this more true than in the Royal Society. The society instituted the method of scientific inquiry most unfavorable to the persistence of dogmatism: laboratory experimentation. To quote past authority was useless, and frowned upon. The crest of the Royal Society bears the motto Nullius in verba ('On the word of no man'). This motto expresses the demand for tangible evidence, for repeatable experimentation, which created the spirit of science, as we know it today.
Royal Society - The Royal Society of London brought together the greatest minds of the region in efforts to advance science through cooperation. The Royal Society of London, and other scientific societies that grew up in Europe during the later seventeenth century, contributed greatly to the scientific progress made during that period.
Doctrine of Uniformity - The doctrine of uniformity was an enormous step in the quest to integrate physics and astronomy. Developed by Galileo in his Dialogue on the Two Chief Systems of the World, the doctrine of uniformity states that corresponding causes produce corresponding affects throughout the universe. Thus, terrestrial physics may be used to explain the motion of heavenly bodies.
Geocentric - The term geocentric describes the theory on the organization of the universe presented by Ptolemy of ancient Greece, and incorporated into the Aristotelian system, which claims that the earth is the center of the solar system and that the sun and other planets orbit around it.
Heliocentric - The term heliocentric describes the correct theory, first posed by Nicolas Copernicus, that the Earth is simply one of several planets which orbit the sun.
Francis Bacon - Bacon (1561-1626) was one of the great philosophers of the Scientific Revolution. His thoughts on logic and ethics in science and his ideas on the cooperation and interaction of the various fields of science, presented in his work Novum Organum, have remained influential in the scientific world to this day.
Galileo Galilei - Galileo (1564-1642) was the most successful scientist of the Scientific Revolution, save only Isaac Newton. He studied physics, specifically the laws of gravity and motion, and invented the telescope and microscope. Galileo eventually combined his laws of physics with the observations he made with his telescope to defend the heliocentric Copernican view of the universe and refute the Aristotelian system in his 1630 masterwork, Dialogue on the Two Chief Systems of the World. Upon its publication, he was censored by the Catholic Church and sentenced to house arrest in 1633, where he remained until his death in 1642.
Johannes Kepler - Kepler (1571-1630) studied the orbits of the planets and sought to discern some grand scheme that defined the structure of the universe according to simple geometry. Though he was unable to do accomplish his goal, he did come up with the laws of planetary motion, which explained the orbital properties of planets, and factored extensively into Isaac Newton's later work.
Three laws of planetary motion:
1. The movement of the planets is a regular elliptical orbit, with the sun as a focus
2. Planets move in a velocity in which equal areas are swept out in equal times
3. The square of the period of the orbit of a planet is proportional to the cube of the planet’s mean distance from the sun.
All heavens are bound in a single mathematical relationship.
Universe was a lawful mechanical system, expressed in mathematics. The model put forth by Copernicus acquired greater status.
Isaac Newton - Perhaps the most influential scientist of all time, Newton (1642-1727) took the current theories on astronomy a step further and formulated an accurate comprehensive model of the workings of the universe based on the law of universal gravitation. Newton explained his theories in the 1687 revolutionary work Philosophia Naturalis Principia Mathematica, often called simply the Principia. This work also went along way toward developing calculus.
Copernicus (1473-1543)
Ptolemy and Aristotle’s work with an overlay of Christian perceptions were the basis of old views of cosmos.
10 heavenly spheres revolved around the immobile Earth and to each sphere were attached heavenly bodies that moved with them. The higher the sphere the more perfect it was and the last sphere was the home of God. The geographical centre was Jerusalem, the holy city.
Circular motion—the motion of the spheres was seen as circular, or perfect.
Humans had special relationship with God, so they were at the centre of the universe.
Proposed the first substantive challenge to medieval cosmology, which had become very complex by the fifteenth century
On the Revolutions of the Heavenly Bodies (1543)- Ptolemaic model was wrong: cosmos is heliocentric (sun-centred) rather than geocentric (Earth-centred).
This system was a hypothesis and it did not provide quantities of evidence from observation to support its claims. Copernicus’s work was controversial.
Natural Rights (from Two Treatises of Government 1690)
Locke believed that humans, in a “state of nature (a time when there was no society or civilization)” are governed by law of nature (reason teaches all mankind that everyone is equal and independent and no one ought to harm another in his life, health, liberty, or possessions.
However, Locke believed that over time, the state of nature would become unsatisfactory and people would become quarrelsome and acquisitive.
They would need a system of government that would guarantee life, freedom, and protection of property; and in establishing a sovereign authority, people retained their natural rights, which they had in the state of nature.
People could not alienate their life, liberty, and property and government existed in order to protect these rights, and therefore, only limited powers were to be given to it.
Social contract was made between individuals to establish an authority and then a contract between the governing authority and the people were made to limit the power of the government.
This ultimately advanced the doctrine of civil liberty.
*more to follow. Made some of the notes by hand in class, so when I get them, I will add more to the page.
Sooo.
Intellectual Elements: (add your stuff underneath)(Ilya) ___
History Notes on Intellectual (1555-1648)
Locke
John Locke (pronounced /ˈlɒk/; 29 August 1632 – 28 October 1704), widely known as the Father of //Liberalism//,[2][3][4] was an Englishphilosopher and physician regarded as one of the most influential of Enlightenment thinkers. Considered one of the first of the Britishempiricists, following the tradition of Francis Bacon, he is equally important to social contract theory. His work had a great impact upon the development of epistemology and political philosophy. His writings influenced Voltaire and Rousseau, many Scottish Enlightenmentthinkers, as well as the American revolutionaries. His contributions to classical republicanism and liberal theory are reflected in theAmerican Declaration of Independence.[5]
Locke Says that and object has certain inherent qualities distinct from perception of it, qualities that it would have even if it were not perceived. The primary Qualities. Size, shape, weight.
Secondary qualities. Color, Smell, texture, taste. These qualities are not within the object itself. We make them up, we get the sensation of them.
Sense Data are the images or sensory impressions, immediate contents of sensory experience. It is not the outer object that is present in the consciousness.
3 Factors involved in perception: Perceiver, knower, the entity or object.
Hobbes
Thomas Hobbes (5 April 1588 – 4 December 1679), in some older texts Thomas Hobbs of Malmsbury,[1] was an English philosopher, best known today for his work on political philosophy. His 1651 book //Leviathan// established the foundation for most of Western political philosophy from the perspective of social contract theory.[2]
Hobbes was a champion of absolutism for the sovereign but he also developed some of the fundamentals of European liberal thought: the right of the individual; the natural equality of all men; the artificial character of the political order (which led to the later distinction between civil society and the state); the view that all legitimate political power must be "representative" and based on the consent of the people; and a liberal interpretation of law which leaves people free to do whatever the law does not explicitly forbid.[3]
Hobbes also contributed to a diverse array of fields, including history, geometry, physics of gases, theology, ethics, general philosophy, and political science. His account of human nature as self-interested cooperation has proved to be an enduring theory in the field of philosophical anthropology. He was one of the key founders of materialism in philosophy.
Descartes
René Descartes (French pronunciation: [ʁəne dekaʁt]; 31 March 1596 – 11 February 1650) (Latinized form: Renatus Cartesius; adjectival form: "Cartesian")[2] was a French philosopher, mathematician, physicist, and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the "Father of Modern Philosophy", and much subsequent Western philosophy is a response to his writings, which are studied closely to this day. In particular, his //Meditations on First Philosophy// continues to be a standard text at most university philosophy departments. Descartes' influence in mathematics is also apparent; the Cartesian coordinate system—allowing geometric shapes to be expressed in algebraic equations—was named after him. He is credited as the father of analytical geometry. Descartes was also one of the key figures in the Scientific Revolution.
Descartes frequently sets his views apart from those of his predecessors. In the opening section of the //Passions of the Soul//, a treatise on the Early Modern version of what are now commonly called emotions, Descartes goes so far as to assert that he will write on this topic "as if no one had written on these matters before". Many elements of his philosophy have precedents in late Aristotelianism, the revived Stoicismof the 16th century, or in earlier philosophers like St. Augustine. In his natural philosophy, he differs from the Schools on two major points: First, he rejects the analysis of corporeal substance into matter and form; second, he rejects any appeal to ends—divine or natural—in explaining natural phenomena.[3] In his theology, he insists on the absolute freedom of God’s act of creation.
Descartes was a major figure in 17th-century continental rationalism, later advocated by Baruch Spinoza and Gottfried Leibniz, and opposed by the empiricist school of thought consisting of Hobbes, Locke, Berkeley, Jean-Jacques Rousseau, and Hume. Leibniz, Spinoza and Descartes were all well versed in mathematics as well as philosophy, and Descartes and Leibniz contributed greatly to science as well. As the inventor of the Cartesian coordinate system, Descartes founded analytic geometry, the bridge between algebra and geometry, crucial to the discovery of infinitesimal calculus and analysis. He is perhaps best known for the philosophical statement "//Cogito ergo sum//" (French: Je pense, donc je suis; English: I think, therefore I am; or I am thinking, therefore I exist or I do think, therefore I do exist), found in part IV of//Discourse on the Method// (1637 – written in French but with inclusion of "Cogito ergo sum") and §7 of part I of //Principles of Philosophy// (1644 – written in Latin).
Gogito Ergo Sum
ogito ergo sum (French: Je pense donc je suis; English: I think, therefore I am), often mistakenly stated as Dubito ergo cogito ergo sum (English: "I doubt, therefore I think, therefore I am"),[1] is a philosophical Latin statement used by René Descartes, which became a fundamental element of Western philosophy. The simple meaning of the phrase is that if someone wonders whether or not he exists, that is, in and of itself, proof that he does exist (because, at the very least, there is an "I" who does the thinking).[2] It forms the bedrock for all knowledge, because, while all things can be questioned as to whether they are from the realm of reality or from some figment of imagination (a dream, influence of a demon, etc.), the very act of doubting one's own existence serves as proof of the reality of one's own existence.
A common mistake is that people take the statement as proof that they, as a human person, exist. However, it is a severely limited conclusion that does nothing to prove that one's own body exists, let alone anything else that is perceived in the physical universe. It only proves that one's mind exists (that part of an individual that observes oneself doing the doubting). It does not rule out other possibilities, such as waking up to find oneself to be a butterfly who had dreamed of having lived a human life.
Descartes's original statement was "Je pense donc je suis," from his //Discourse on Method// (1637). He wrote it in French, not in Latin and thereby reached a wider audience in his country than that of scholars. He uses the Latin "Cogito ergo sum" in the later //Principles of Philosophy// (1644), Part 1, article 7: "Ac proinde hæc cognitio, ego cogito, ergo sum, est omnium prima & certissima, quæ cuilibet ordine philosophanti occurrat." (English: "This proposition, I think, therefore I am, is the first and the most certain which presents itself to whomever conducts his thoughts in order."). At that time, the argument had become popularly known in the English speaking world as 'the "Cogito Ergo Sum" argument', which is usually shortened to "Cogito" when referring to the principle virtually everywhere else.